Mast antenna



July 20, 1948 R. E. KESTER Er AL 2,445,329

MAST ANTENNA 2 Sheets-Shea?I 1 Filed March 25, 1944 Flsa/ 'B INVENTOR.

yROBERT E. KEsTER WILLIAM s. Qumcm /Q-Z@ @4f/Mx ATTORNEY July 20, 1948.R. E. KESTER Er AL 2,445,329

MAST ANTENNA oBERT E. KESTER ATTORNEY WILLIAM S.QUINCY,JI?`

Patented July 20, 1948 MAST ANTENNA Robert E. Kester and William S.Quincy, Jr.,

Dayton, Ohio Application March 25, 1944, Serial No. 528,056

(Cl. Z50-33) (Granted under the act of March 3, 1883, as amended April30, 1928; 370 O. G. 757) 2 Claims.

The invention described herein may be manufactured and used by or forthe Government for governmental purposes, without the payment to me ofany royalty thereon.

` This invention relates to mast antennas and more particularly to amast antenna for use on aircraft and the like.

'The objects of the present invention include the provision of aproperly functioning, rugged and durable mast antenna that comprises aminimum number of securely joined parts that are adapted for simple andrapid manufacture and assembly; a mast antenna that is sufficientlyreinforced to withstand prolonged exposure to vibration and the like,and to provide a long period of service.

With the above and other objects in view which will be apparent to thosewho are informed in the iield of development in which the presentinvention belongs, an illustrative embodiment of the Apresent inventionis presented in the accompanying drawings, wherein:

Fig. 1 is a fragmentary foreshortened side elevation of a mast antennathat embodies the present invention;

Fig. 2 is a fragmentary foreshortened edge elevation view of the mastantenna that is shown in Fig. 1;V

Fig. 3 is a plan view of the Contact carrying connecting plate mountedon the base of the mast antenna that is shown in Fig. 1;

Fig. 4 is a section taken along the line 4-4 in Fig. 1;

Fig. 5 is an enlarged side elevation of a current carrying assembly formounting within an axially extending aperture in the base of the mastantenna that is shown in Fig. 1; and

Fig. 6 is a diminished side elevation of the plated stai of the mastantenna that is shown in Fig. 1.

The mast antenna that is shown in the accompanying drawings comprises atapered and streamlined mast staff I, that extends continuouslythroughout the length of the antenna and that preferably is made ofcompressed phenolic impregnated plywood, although it may be of plasticor other composition and solid or hollow, as preferred. The phenolicimpregnated plywood of which the mast staff I is made, preferably iscompressed so that its specic gravity is graduated from a maximum valueat the zone of maximum stress of the mast antenna to a minimum value atits tip. A mast antenna that embodied the present invention was found tohave a specie gravity of 1.2 at its zione of maximum stress decreasinggradually to a specific gravity of 0.9`

at its tip. j The mast staff I is surfaced in any desired manner with atightly joined skin or sheath 2 that encloses the tip end of the staff Iand that extends continuously longitudinally of the -mast staff for adistance that preferably is substantially a fraction of, or a multipleof the wavelength of, the electrical impulses that it is to conduct. Themetal skin or sheath 2 is preferably firmly bonded to or closely fitupon the surface of the mast staff I as by being electroplated, metalsprayed, or otherwise deposited thereon or secured thereto. When it isdesirable to have a wire attached to the tip of the mast antenna, agrommet or brass tube 3, that is secured in place by being flared atboth ends, as shown, or the like, is disposed within a Wire receivingaperture adjacent the tip of the mast stai I and makes continuouselectrical contact with the metal sheath 2.

The base of the mast staff I is drilled longitudinally to receive asuitable conducting cable assembly that comprises an inner cable 4 thatis connected electrically at one end to the metal sheath 2 in anysuitable manner, as thru the slug 5 that is soldered to the cable 4 andis tapped to receive the threaded tip of a screw 6 that is in contactwith the sheath 2, or the like. The screw 6 extends transversely of themast staff I along the longer dimension thereof and its head portion isin electrical connection with the metal sheath 2. as by being solderedthereto, mounted in place during the deposition of the sheath 2, or thelike. The opposite end of the inner cable 4 makes electrical connectionwith a central contact 1 that preferably comprises an axially splitconical hollow sleeve opening outwardly of the assembly or of otherdesired type of contact. The inner cable 4 is preferably disposed Withinan insulating tube 3, outwardly of which is disposed a woven copperhollow cable 9 that has a slug I0 soldered to its inner end. The slug I0is tapped for the reception of the inner end of a screw II that extendsto the outside of the mast stati' and that is provided at its exposedend with suitable means, such as a pair of nuts I2, or the like, forsecuring a ground connection (not shown) to the screw II so that whenthe antenna is installed the screw II may be grounded to the skin of anairplane upon which the mast antenna is mounted or to other electricallygrounded part.

The outer end of the woven hollow cable 9 makes electrical connectionwith a tubular part I3 of a plate I4, as by being soldered thereto orthe like. The rim of the plate I4 faces against a plate I5 ofsubstantially the same peripheral dimensions. Both the rim of the plateI4 and the plate I5 are apertured for the disposition of screws I 6 orthe like therein for securing the plate rim I 4. and the plate I5 upon.the ilat face of the base of the mast staff I. The plate I5 is integralwith a cylindrical ground connection I'I that is concentric with andinsulated from the` central contact 'I. The cylindrical groundconnection II terminates at its free end in a plurality of teeth I8.Another outer insulating tube I9 is disposed outwardly of the wovenhollow cable. 9.

The center of gravity of the mast antenna preferably is positionedsubstantially as indicated by the intersection 20 in Fig. 6. Supportingclamps 2I for stabilizing the mast antenna in its mounted position areindicated in dottedk outline in Fig. 6 of the drawings.

It will be understood that the details of construction that have been.shown and described. herein. have been submitted for the purposes ofillustrating and describing an embodiment of the present invention andthat modifications and refinemente may be made therein Without departring from. the invention as. defined by the appended claims.

What we claim is:

1. A mast antenna, comprising in combination a mast sta-fi of phenolicimpregnated plywood compressed to a maximum density at substan tiallythe zone of greatest stress thereof, an el-ectri-cally conducting sheathoverlying and supported by a portion of the outer surface oi said maststaff, av cable assembly disposed Within an apcr ture extendinglongitudinally of said mast staff and opening outwardly through the baseportion thereof, an inner cable part of said cable assembly extendingsubstantially longitudinally thereof, a tapped and threaded rst slugsoldered to said inner cable at substantially an inner end thereof, acentral contact accessible from outwardly of said mast antenna anddisposed at an outer end of said inner cable, a iirst screw inelectrical connection. with said sheath and threaded into said rstslug', a woven hollow cable insulated from and substantially' coaxialwith. said inner cable and extending longitudinally thereof, acylindrical insulating tube extending longitudinally of both said innercable and said Woven hollow cable and interposed therebetween, a secondtapped and threaded slug soldered to said Woven hollow cable atsubstantially an inner end thereof, a second screw having one endthreaded into said second slug and having an opposite end extending tothe outside of said mast staff, a ground connection at an outer end ofsaid woven hollow cable and accessible from outwardly of said mastantenna, and means insulating said central contact from said groundconnection.

2. An antenna for radiating electrical energy, comprising in combinationa staff of electrically insulating material, a base portion of saidstaff through which an aperture that extends longitudinally of saidvantenna opens, an electrically conducting sheath bonded closelythroughout its inner surface to said staff upwardly from the baseportion thereof, an electrically conductive terminal assembly disposedwithin the aperture in said antenna, a central connection portion ofsai-d terminal assembly accessible from outwardly of the base portion ofsaid staff, a ground connection portion of said terminal assemblyaccassible from outwardly of the base portion of said stai and insulatedfrom said central connection portion of said terminal assembly, meansconnecting said central connection tol said sheath. and groundconnection connecting means insulated from said central connectionsheathconnecting means and accessible from outwardly of said staff baseportion.

ROBERT E. KESTER. WM. S. QUINCY, JR.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATE PATENTS Number Name Date 1,962,227 Zepler June 12, 19341,976,804 Ringel Oct. 16, 1934 2,251,708 Hefele Aug. 5, 1941 ,2,266,139Zukerman Dec. 16, 1941 FOREIGN PATENTS Number Country Date 548,244 GreatBritain Oct. 2, 1942 502,460 Great Britain Mar. 17, 1939

